console.log(Buffer.alloc(10))
console.log(Buffer.alloc(20))
console.log(Buffer.alloc(5,1))
console.log(Buffer.alloc(5,'a'))
console.log(Buffer.allocUnsafe(5,1));

console.log(Buffer.from([1,2,3]));
console.log(Buffer.from('abc'))
console.log(Buffer.from('abc','base64'))